Study On The Meshing Characteristics And CAD Technique Of Cycloidal Gear Pump

Internal meshing gear pump is the important equipment in hydraulic drive and control, media transmission, metering, and other fields, because its advantage of small size, light weight, low noise, self-absorption, good flow pulse and so on, it is widely used in petrochemical, aviation, shipping, energy industry and other important areas of the national economy. However, machining is more difficult due to its complex tooth profile, the domestic research and development are behindhand. With the continuous development of science technology and application, some new research and development technologies have emerged. As the important means of designing and developing new products, CAD and CAE technologies have played a significant role in the promotion for research and development of internal cycloidal gear pump. The meshing characteristics, tooth root stress analysis, wheel tooth profile parametric drawing are systematically studied in this paper, these researches are the basis and the key to develop internal cycloidal gear pump. The main researches done in this paper are:(1) Based on the meshing characteristic of internal cycloidal gear pump and meshing theory, the tooth profile equation of cycloidal gear is derived, the meshing characteristics such as meshing limit, contact ratio and so on are analyzed, the construction method of fillet curve is discussed, the effective range of theoretical tooth profile is obtained based on the numerical calculation, the design theory and method of the internal cycloidal gear pump are improved. (2) Based on the analysis of tooth profile equation and the fillet radius, the program of parametric drawing for the complete tooth profile of cycloidal gear is developed, the coordinate points of tooth profile and 3D modeling generated by the program contribute the foundation of NC machining and stress analysis.(3) Aimed at the features of less teeth and large module of internal cycloidal gear, using SolidWorks and ZRCAE platform, the CAE model of cycloidal gear is established, the effects on root stress of the fillet arc type, fillet radius and hydraulic pressure are analyzed.(4) Based on the meshing characteristics, the flow characteristics of internal cycloidal gear pump are analyzed, the formula calculating the instantaneous flow is derived, theoretical model of flow pulse rate is established, the design and analysis precision of internal cycloidal gear pump is improved.(5) Subjected to the meshing conditions, strength requirement, tooth profile restrictions of internal gear, an objective function maximizing disposition volume is established in this paper, the optimal design of geometric parameters of the gear pump is achieved through the Visual Basic programming.